'Politics rather than bed I imagine. Although, when it comes to sex, nothing is too bizarre to be ruled out. Police work teaches you that if nothing else. She could have taken a fancy to being Lady Ralston. There must be easier ways of getting money than running a detective agency. And Ralston will have money, remember. His wife's, to be specific. And I don't suppose that will come before it's needed. He must be spending a packet on that organization of his – the UBP or whatever they call it. And that's an odd business if you like. I suppose you can argue a case for an amateur force trained and ready to support the civil power in an emergency, but isn't that what General Walker has in hand? So what exactly do George Ralston and his geriatric conspirators think they're up to?'

As Buckley didn't know the answer and had, in fact, hardly heard of the Union of British Patriots, he wisely kept silent. Then he said:

'Did you believe Gray when she said that Sir George thought that she was confessing?'

'What Miss Gray thought she saw in Sir George's face isn't evidence. And no doubt he did look amazed if he thought he heard her confessing to a murder he'd done himself.'

Buckley thought about the girl who had just left them; saw again that gentle, uplifted face, the immense and resolute eyes, the delicate hands folded like a child's in her lap. She was keeping something back, of course; but didn't they all? That didn't make her a murderess. And the idea of her and Ralston together was ludicrous and disgusting. Surely the Chief hadn't yet reached the age when he needed to start believing that pathetic old lie with which the middle-aged and the elderly deceived themselves, that the young find them physically attractive? What they can do, the old goats, he told himself, is to buy youth and sex with money and power and prestige. But Tie didn't believe that Sir George Ralston was in that market or that Cordelia Gray could be bought. He said stolidly:

'I can't see Miss Gray as a murderess.'

'It takes an effort of the imagination I grant you. But that's probably what Mr Blandy thought of Miss Blandy. Or L'Angelier of Miss Madeleine Smith, come to that, before she so unkindly handed him his cocoa and arsenic through the basement railings.'

'Wasn't there a verdict of not proven in that case, sir?'

'A fainthearted Glasgow jury who should have known better and probably did. But we're theorizing in advance of facts. We need the PM result and we need to know what, if anything, was in that tea. Doc Ellis-Jones will probably get her on the slab tomorrow, Sunday or no Sunday. Once he's got his hands on the body he's quick enough at his butchering, I'll say that for him.'

'And the lab, sir. How long are they likely to take?'

'God knows. It's not as if we've any idea what they're supposed to be looking for. There isn't an unlimited number of drugs which can put you out, or kill you, within a short time and with no obvious signs on the body. But there are enough to keep them busy for the next few days if this is the only murder on the stocks. We may get a clue from the PM of course. Meanwhile we get on with the London end. How well did any of these people know each other before they arrived on the island this weekend? What, if anything, do the Met know about Cordelia Gray and her agency? What did Simon Lessing really feel about his benefactress and how, exactly, did his father die? Is Miss Tolgarth quite the devoted dresser cum family retainer that we're supposed to believe? What sort of money is Sir George spending on his toy soldiers? How much exactly is Roma Lisle going to get under the will and how badly does she need it? And that's just for starters.'

And none of it, thought Buckley, was the kind of information people came running to give you with happy smiles. It meant talking to bank managers, lawyers, friends, acquaintances and colleagues of the suspects, most of whom would know to a word just how far they needed to go. In theory everyone wanted murderers caught, just as in theory they all approved of hostels for the mentally ill in the community, provided they weren't built at the bottom of their garden. It would be simpler for the police as well as reassuring to the house party at the castle if they did discover those convenient young burglars hiding terrified somewhere on the island. But he didn't believe that they existed and nor, he suspected, did anyone else. And it would be a tamely disappointing ending to the case. What glory would there be in pulling in a couple of terrified local villains who'd killed on impulse and wouldn't have the nous even to keep their mouths shut until they got a brief. There was an intelligence at work here. The case was exactly the kind of challenge he enjoyed and which police work so seldom provided.

'There are facts. There are suppositions. There are beliefs. Learn to keep them separate, Sergeant. All men die: fact. Death may not be the end: supposition. There's pie in the sky when you die: belief. Lisle was murdered: fact. She received anonymous communications: fact. Other people were there when they arrived. They threatened her life: supposition. They were a bloody sight more likely to put her off her stroke as an actress. They terrified her: supposition. That's what her husband tells us and what she told Miss Gray. But she was an actress, remember. The thing about actresses is that they act. Suppose she and her husband concocted the whole scheme, threatening messages, apparent terror and distress, breakdown in the middle of a play, calling in a private eye, the lot.'

'I don't see why, sir.'

'Nor do I, yet. Would any actress willingly humiliate herself on stage? God knows. Actors are an alien breed to me.'

'If she knew that she was finished as an actress, could she and her husband have concocted the messages to provide a public excuse for failure?'

'Over-ingenious and unnecessary. Why not just pretend that her health has failed? And she didn't make the messages public. On the contrary, she seems to have taken care to prevent the news getting out. Would any actress wish her public to know that someone hated her that much? Don't they crave to be loved by all the world? No, I was thinking of something rather more subtle. Ralston somehow persuades her into pretending that her life is threatened, and then kills her, having, as it were, seduced her into conniving at her own murder. My God, that would be neat. Too neat, perhaps.'

'But why take the risk of calling in Miss Gray?'

'What risk? She could hardly discover that the letters were faked, not in one short weekend. A very, short weekend as far as Lisle was concerned. Employing Gray gave the final artistic touch to the whole plan.'

'I still think he'd have been taking a risk.'

'That's because we've seen the girl. She's intelligent and she knows her job. But Ralston wasn't to know that. Who was she, after all? The proprietor of a one-woman detective agency, apparently. After Lisle first met her at the house of that friend of hers – Mrs Fortescue wasn't it? – she probably suggested to Ralston that they call her in. That's why she never bothered to interview the girl herself. Why trouble when the whole thing was a ploy?'

'It's ingenious, sir, but it still begs the question why Lisle should have connived in it all. I mean, what possible reason could Ralston give to persuade her to pretend that her life was threatened?'

'What, indeed, Sergeant? Like Miss Gray, I'm in danger of being too clever for my own good. But one thing I'm sure of. The murderer spent the day under this roof. And I've a choice bunch of suspects. Sir George Ralston, baronet, something of a war hero and darling of the geriatric Right. A distinguished theatre critic, one even I have actually heard of. Seriously ill too, by the look of him, which means that he'll probably die on me under the gentlest interrogation. Interrogation. Odd how one dislikes that word. Too many echoes of the Gestapo and KGB I suppose. A best-selling novelist who not only owns the island but happens to be friendly with the Cottringhams who have the ear of the Lord Lieutenant, the Chief Constable, the MP and anyone else who matters in the County. A respectable bookseller ex-schoolteacher who's probably a member of the civil rights and women's lib lobbies and who will protest to her MP about police harassment if I raise my voice to her. And a school kid – and sensitive with it. I suppose I should be grateful that he's not a juvenile.'